The error 815 indicates some sort of network connection issue. It is network related, a loss of connection, temporary lag or perhaps server is not responding. The system will attempt to reconnect. If the reconnect is not successful, then there is network or server issue. Check your internet connection to other websites. If the internet is ok, then it is most likely the connection to the server or the server itself.

It could also be the hosting company settings limits as well. Contact your hosting company if there are throttle limits being reached on your account or any indication of error in the server error log file.